Browse Prior Art Database

Efficient High Voltage Driver With Low Voltage Input

IP.com Disclosure Number: IPCOM000046678D
Original Publication Date: 1983-Aug-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 27K

Publishing Venue

IBM

Related People

Barcomb, JG: AUTHOR [+3]

Abstract

An efficient high current driver circuit is formed from three transistors. One of the transistors is used as a low input stage, while the other two transistors are coupled in a darlington-type configuration to form the output stage of the circuit. A low value resistor interconnects the input stage of the circuit to the output stage. A graphical representation of the circuit is given in Figs. 1 and 2. In Fig. 1 the supply voltage (+V) is positive, while in Fig. 2 the supply voltage (-V) is negative. Transistors T2 and T3 are connected in a darlington-type configuration. R3 ties the base of T3 to ground, while R2 ties the base of T2 to the output node (V out). T1 forms the input stage of the driver circuit. R1 ties the collector on T1 to the base of T2.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Efficient High Voltage Driver With Low Voltage Input

An efficient high current driver circuit is formed from three transistors. One of the transistors is used as a low input stage, while the other two transistors are coupled in a darlington-type configuration to form the output stage of the circuit. A low value resistor interconnects the input stage of the circuit to the output stage. A graphical representation of the circuit is given in Figs. 1 and 2. In Fig. 1 the supply voltage (+V) is positive, while in Fig. 2 the supply voltage (-V) is negative. Transistors T2 and T3 are connected in a darlington-type configuration. R3 ties the base of T3 to ground, while R2 ties the base of T2 to the output node (V out).

T1 forms the input stage of the driver circuit. R1 ties the collector on T1 to the base of T2. When the transistors are saturated V outsat = VBE T3 + VCE T2 = VBE T2 + VCE T1 + I R1 By selecting the value of R1 to be relatively low (between 10 and 50 ohms), when the circuit is in saturation, R has very little effect on the output saturation voltage. The circuits of Figs. 1 and 2, require relatively low input voltage VIN for turning on. Also, all the transistor collector currents pass through the load and none are wasted. When the circuit is off, only leakage current dissipates power.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]